Sometimes I see videos on YouTube in which these people proclaim that we "can do it, using geothermal, wind and solar and conservation..." but I never see any mathematical substantiation for these claims. And if there's any, they omit thermal energy. Dogmatism and delusion go hand in hand.
The narrative of these groups is a driving force behind the consolidation of the power and the influence of the Fossil Fuel industrials. Why? Because renewable energy is useful, but not strong enough to defeat thermal energy and the exploiters of the earthly resources know it... I'm not as influential as any of these people, but I am proud to tell you that I try to wonder, and ask questions. I ponder on important matters and postpone judgement until I have examined the evidence and the science behind it, and when I feel comfortable enough I will take on a stance [be it tentatively].
What technologies are capable of generating / harvesting energy and converting it into electricity, without [direct] tail-pipe emissions :
Solar Energy (Panels & CSP)
And then there's special case regarded by many as renewable, and the fastest growing of them all... [tail pipe emissions and all sorts of problems attached]
Biomass (Trees, and other burnable stuff...)
The generation / capacity paradigm
Lets clarify something : Most websites focussed on renewable energy tell us how much capacity has been added in year X. This is a fundamental flaw and is misleading people into believing that the renewable additions are substantial. There's a clear negative correlation between capacity and electricity generated. The main driver behind this dichotomy is a thing called "capacity factor". Capacity factor is the time when a piece of technology is generating electricity.
Suppose it is a 1000MW rated facility, it has a capacity factor of 80% : (8766/100) x 80 = 7012 hours x 1000 = 7.012.800 MWh or 7 TWh.
Compare this to a 1000MW solar facility with a capacity factor of 20% : (8766/100) x 20 = 1753 hours x 1000 = 1.753.000 MWh or 1.7 TWh
Now both technologies are rated at the same capacity, but there's a sharp discrepancy of about 5 TWh at the end of a year... This is the reason why we need to leave the capacity for what it is. The total sum annual output is what counts : TWh (after 8766 hours, or a year, have passed).
Another strange paradigm is the amount of electricity generation envisioned by a lot of environmentally conscious groups, they tend to end up with a figure somewhere between the 4 and 8 TW capacity. Now this is childishly easy to trace back... We currently consume about 21.000 TWh of electricity each year. 21.000/((8 TW x 8766)/100) = 29% -- a reasonable figure when considering an energy mix of renewable energy sources with capacity factors ranging from 15 to 70%.
There are some fundamental flaws in this line of reasoning :
- They want to decarbonize energy but omit the 850 Quadrillion BTu figure which translates into 240.000 TWh
- They suppose that everything is possible based on financial arguments yet omit resource requirements
- The end of certain fossil fuel resources is in sight, it is expected that Natural Gas and Oil will run out in a matter of decades, maybe even five or six, given current production rates and known reserves. Thus forcing us to look at the 240.000 TWh picture, rather than the 21.000 TWh
- It is unreasonable to suppose that there are limitless deposits of anything...
Not to look at the 240.000 TWh picture is to be intellectually dishonest or terribly misinformed, not having a proper understanding of energy consumption rates, and what are energy demand drivers. Let's brake it down :
- We currently consume about 650 Quadrillion BTu (source : EIA)
- This is equivalent to 190.000 TWh
- We currently generate about 21.000 TWh of electricity
- Electricity is 11% of the total energy consumption in the world.
- Roughly 60~65% of electricity production is thermal (non-nuclear) (Coal, Gas and Oil)
- 93.4 % of all energy generation comes from burning Coal, Gas and Oil...
(These numbers fluctuate each year)
Simply look at this article, there are thousands of them. They all mislead you into thinking that solar will be able to play a dominant role, if only we ...
- Had the batteries...
- Could produce a gazillion of them...
- Had those pixie dust panels that could capture all of the radiation that strikes it...
We should all listen to good old FDR
(Four terms as president of the United States!)
Let's have a deeper look at the technologies involved and the limitations imposed.
Solar : a brief look
The earth receives about 1.4 Kilowatt of solar energy per square meter (optimum). Multiplying this number by the total surface of the Earth gives us a figure a billion times more than humanity requires. So it's possible, right? Wrong!
Suppose we can capture all those Kilowatts, suppose we build square meter panels that harvest those 1.4 Kilowatts. Suppose we could fill 10.000 TWh's worth of annual generation capacity by implementing these 1.4 Kilowatt panels. Now a panel can harvest this energy roughly 8 hours a day according to this diagram found here : http://www.pveducation.org/pvcdrom/properties-of-sunlight/average-solar-radiation
So how much energy would a 1.4 KW / M2 panel yield in a year?
1.4 x 2922 hours (one third of 8766 hours) = 4090 KWh or 0,00000409 TWh
Now there's one amendment I need to make here, as seen in the figures provided by the EIA the capacity factor of most PV fluctuates around 20% and not 33%...
1.4 x 1753 hours (one fifth of 8766 hours) = 2454 KWh or 0,000002454 TWh
I will dub these panels "pixie dust" panels. How many "Pixie Dust" panels would we need to satiate 10.000 TWh? Four billion, seventy five million. (rounded up) Most PV panels are about .72M2 which increases the number to above 6 Billion. These panels do not exist, the maximum capture capability of PV panels is about 200~250 watts per 0.72 M2. Nobody knows what kind of advances and elements would be required to build these "pixie dust" panels. but we will have to find out. Because we are in need of all "non-carbon-emitting" technologies. Especially because of different circumstances. And in this quest we should always push for the highest possible yields and efficiencies, thus minimizing the material requirements.
Please note that 10.000 TWh's of electricity generation is by no means enough. The EIA extrapolates that by the 2040's we will need about 240.000 TWh of annual energy generation. Our true energy problem is 25 times larger than my theoretical chunks of 10.000 TWh.
The maximum effiency currently in sight for PV technology is 50%. The material required for this technology is called Perovskite. This means that we have a potential maximum capacity of 0.7KW per square meter, but the technology is still very immature and it depends on Titanium, which is terribly hard to obtain. Suppose we could get it, develop it and implement it, we would still need roughly ten billion panels to be able to generate 10.000 TWh each year.
Let's have a look at some different Photo Voltaic (PV) technologies :
CdTe Photo Voltaic Panels
Are there limitations to renewable growth? Let's start with the easiest, shall we?
CdTe PV panels. CdTe stands for Cadmium Telluride PV panels. CdTe panels are among the most effective and are easy to produce. To build a PV plant of CdTe panels we need the following : silica, concrete, non zinc coated steel, aluminium, copper, glass and cadmium and tellurium. There's probably a couple of other materials and substances but these are the most important. Which is the limiting material in the chain? It's Tellurium. Annual tellurium production fluctuates between 125 and 200 metric tons. 1 GW worth of CdTe panels contains about 90 metric tons of Tellurium. 1 GW is about 18 million CdTe panels (reckoning by Topaz PV plant standards). This means that in an optimistic scenario we could add 2.5 GW of CdTe panels annually or 45 million panels equivalent or about 5 TWh of annual electricity generation.
The availability of Tellurium mainly depends on copper mining activities. Out of a staggering 18.3 million metric tons of copper mining, Tellurium optimally is a 250 tons by-product... Boosting Tellurium production would mean a steady increase in strip-mining activities, hardly a green activity. CdTe panels are realistically speaking capped at a maximum of 5TWh's of added capacity, give or take 10~15%.
The truly sad part is that we can add ~8TWh by constructing any 1 GW unit that runs for 90% of the time. If we would build a AP-1000 reactor facility for instance, it would not use 100% of all the available resources (like Tellurium) and produce much more energy in one year, than 45 million CdTe panels would do.
Conclusion about CdTe PV panels : they are not going to make a dent in our energy problem.
Copper Indium Gallium Selenide Photo Voltaic Panels (CIGS)
Together with the CdTe type panels Copper Indium Gallium Selenide (CIGS) Panels are the most widely distributed panels. Copper and Indium availability limit the production volumes.
Lets hammer the figures home, copper is already stressed out, we're running out of goldilocks deposits.
Indium is a byproduct of lead, tin, zinc, copper and Iron production. We currently produce around 700 tons each year. Indium isn't that rare, but it is thought that we might run out within a timespan of two decades. Indium is mainly used in electronics.
Selenium is quite ubiquitous at this moment, production levels lie around 2.000 tons annually. It is estimated that there is 93.000 tons left.
The figures are quite clear, it isn't as if we have thousands of tons of the stuff lying around. These industries are dependent on the production capabilities of the mining and ore-processing industry, and these capabilities are limited, and rightly so. We could easily dig up much more materials if we disregard financial limitations and the consistency of nature.
Aside from CdTE and CIGS PV panels there are other panel types that are equally limited due to a great number of factors :
- Material dependencies
- High production costs
- High waste volume during production
- High energy requirements during manufacturing
- low yields
- Low space-efficiency
- Degradation issues
- Utilization and creation of hazardous materials
Deployment speed of PV
Let's have a look at a recently published article. SolarCity (co-owned by Elon Musk) has announced that they will be introducing a new kind of PV panel that has an efficiency of 22,04% (which means it captures 22.04% of the 1.4 KW striking the Earth.) and they are aiming for a daily production volume of 10.000 units.
Let's brake this down, Elon Musk's involvement guarantees a lot of publicity (some people were sending me this article...) , but is it really worth it?
I suppose that this panel will have a surface area of about 0.72M2, which is roughly the industry standard. 22.04% of 1.4 KW = 0.308 KW and 0.72M2 = 0.222 KW or 222 Watt. At a daily production rate of 10.000 units they will be producing 3.650.000 units annually which amounts to 0,79 GW added capacity each year. That equivalent to 1.385 TWh's worth of added generation capacity each year.
Hardly an article worth getting excited over. I would love to know what kind of PV panel they are going to produce and what the production cycle looks like and which materials would be used.
What do other articles tell us? The Indians are building the biggest utility scale PV plant to date, a staggering 4 GW. How long does it take to build this 4GW power plant? 7 years... A potential 6.941 TWh worth of energy generation capacity added in 7 years.
The construction of the Topaz PV plant in California, rated at 550 MW and producing about 1 TWh annually, started in November 2011 and finished in November 2014. Took three years to complete and only utilizes CdTe panels.
Does it start to sink in? The volumes involved, the limitations involved really hinder PV technology to be implemented as fast as it needs be. Furthermore there's a psychological effect to it. This is the best and most optimistic news they can come up with. What does this tell you?
They are truly limited, if there were no limitations, solar production and implementation would be exploding right now, but it isn't. Even though many of the solar-acolytes like to make it seem that it does...
Let's take a look at the industries most telling graph :
In 2014 the solar industry added another 40 GW (69.4 TWh) worth of capacity to the grid taking it up to 180 GW. 180 GW of capacity equals 312 TWh worth of generation capacity or 1.5% of the total 21.000 TWh. In and of itself this graph looks impressive, it's an incline. I want to know where on the graph the limitations will manifest themselves? I expect that at some point the curve will bend down again.
And what would this graph look like if we included all the other electricity generation capacity?
This graph paints a different scenario, source : http://oneinabillionblog.com/summary-2/collapse/expensive-energy/
This graph is more comprehensive than the BP one, it differentiates the energy sources more clearly and shows a big push for biofuels, solar, wind, geothermal and nuclear energy. Where I am quite confident that Geothermal would take a larger portion of the yellow part of the graph, than one would be inclined to think. The disconcerting thing is that all these viable alternatives to the finite fossil fuel generation only achieve two-fifths of the total energy production by the 2050's. And there are reasons for it.
Deployment speed is everything. Since there are hard natural caps imposed on technologies like Biofuels, Hydro, Solar, wind and Geothermal. These technologies are limited by factors like availability of resources, production capabilities, transportation requirements, surface requirements, and geological constraints.
Resource requirements for utility scale PV
Building PV installations is not just slamming some PV panels on a roof and connecting them. They require aluminium railings, copper wiring and AC/DC converters. If we ramp it up to utility scale the requirements become much bigger : Concrete, Steel, Aluminium and copper : LOTS.
Figuring out the requirements for the 10K TWh challenge starts of with these kinds of tables :
(Pay special attention to the red square)
From this table something becomes clear straight away : steel, copper and concrete are vital materials required to realize utility scale PV plants. I'm quite confident that the numbers will be almost the same for different types of panels. I Do not expect mounting and cabling requirements to go down even if different technologies have a slightly higher efficiency. The KG/M2 requirement will remain the same.
Also consider the red square, these are on-site construction emissions... Suppose you have a PV plant like the Topaz PV plant it would require 25.000.000M2 x 1.590KG = 39.750.000 KG of Diesel required to construct the Topaz PV plant...
1 KG of Diesel equals 1.1299 Liters
If the combustion of diesel is efficient one would release 2640 Grams of CO2 per liter of combusted diesel. (source : http://www.ecoscore.be/en/how-calculate-co2-emission-level-fuel-consumption)
This would mean that in order to construct this PV plant, we would be emitting another 118.571.706 KG of CO2. On the grander scale of things, this is not a lot, but it certainly disproves the claim that renewable energy comes without environmental costs.
One thing becomes clear from this exercise, it is a fundamental falsehood to presume that renewable energy such as solar is emissions free. The rest of the materials will return later on.
Hydro : Maxed out
Hydro power is pretty much maxed out. Our hydro-power practices have inflicted much harm on nature by disrupting the hydrological cycles of the world. Hydro is also becoming increasingly more unreliable given the increased droughts all over the world. Changing precipitation patters, increased warm periods and droughts erode the availability of a volume of water that is suitable for kinetic transition. Hydro in its current context is set to go into a slow and gradual decline as fresh water crises are developing all across the world.
Geothermal : A very promising tech with limited deployability
Geothermal is a mature and reliable technology. It is basically a generator without a furnace. You stick a pipe in the ground, deep enough so that it reaches high temperatures in the Earth's crust, and then transports that heat back up in order to turn a steam-generator. The heat comes mainly from the decay of radioactive isotopes like Potassium and Thorium. The problem with this technology lies within the depths that need to be reached in order to get enough energy "back up" to generate electricity, or to use for other purposes.
Geothermal can be used to heat or cool homes, and to generate electricity.
I have high hopes that Geothermal will become the dominant form of renewable energy somewhere in the distant future i.e. the future energy mix will probably be dominated by Nuclear and Geothermal energy rather than Hydro, Wind and Solar.
Wind Turbines is the pet technology of the renewable movement. It's wind and it's sun that is going to save us according to environmental groups like Greenpeace, Sierra Club or the WWF.
Looking for some material requirements on Wind Turbines, I found this document :
(If you have any more recent ones, please feel free to share them with me!)
This is the table that I was looking for :
I feel generous today, I'm going to run with the "next generation" figures. Suppose we would build 10.000 TWh's worth of wind turbine generation at a rated capacity factor of 35%.
How many units would we have to build? 2.3 Million 2.5 MW units
Neodymium production fluctuates between 10.000 and 15.000 tons annually. Which means that there's a 15 million KG cap on Neodymium annually. Normally around 20% of this stockpile is being used by the wind-energy industry. The rest has to be divided by BEV manufacturers and other electronics. Which means that there's 3.000 tons available annually, which in term means that you can not add more than 70.000 MW capacity a year. Which is about 28.000 2,5 MW wind turbines. By this reckoning It would take 81 years to get 10.000 TWh's worth of Wind Turbines constructed. And in this case I omit cumulative replacement requirements, which need to be done every 15 ~ 20 years per unit which means that after 15 years the production capacity of wind turbines should start to double as replacing the first units becomes necessary.
The cap on wind-energy additions is ~ 125 TWh annually.
Unless we accept that there are more expensive and/or less efficient ways to capture wind energy - without Neodymium. But we're already stretching it thin as it is.
Some interesting reads on Neodymium and other Rare Earth Materials :
In the case of Neodymium we'll be arriving on a crossroads quite soon. Will we progress on building low capacity intermediate energy generators or will we move on and keep investing in the BEV movement, which I think would be the far wiser course to pursue. One thing is certain, you can't have it both ways...
We now know some of the limiting factors in the world of renewable energy. This means that we can derive some conclusions.
How do these technologies stack up against each other?
Most people like to take this through from the per megawatt viewpoint. I address it differently, since I want to make a "per annual generation capacity" comparison. I think these metrics give a better view and clearly envision what we're up against if we want to decarbonize the entire energy industry. I will introduce my wildcard at this point : nuclear energy.
Lets start by looking how much capacity is required to generate 1 TWh of energy Annually per technology :
Secondly lets have a look at the materials footprint per TWh per technology and compare them.
These are my sources :
Now we're going to expand this to the 10.000 TWh mark for each relevant technology, since we are fully decarbonizing, which is a necessity. And forget about synthetic fuels, they will drive the electricity demand through the roof.
I've deconstructed the above table and created my own. So how much materials are required to build a generation capacity of 10.000 TWh?
From these numbers it becomes quite clear that in order to build facilities that can generate 10.000 TWh on an annual basis, you need a lot of materials :102.6 million tons for wind, 164.5 million tons for solar, 52.6 million tons for Geothermal and a mere 9.3 million tons for nuclear.
This is a good analogy to show what people mean by energy density. The technology with the highest possible energy density requires the least amount of materials to get build.
I submit to you that it is not possible to defeat fossil fuels, at least not in a timeframe that is of any meaning in our plight against Anthropogenic Climate Change and the yearly death toll from the combustion economy. Is it possible to go 100% renewable? I do not think that it is possible, the demand for energy is too high and the punch delivered by renewables is far too low. From my 10.000 TWh block philosophy we get a new perspective on the material requirements to realize these generation capacities. We can extrapolate these figures upwards to 100.00 TWh, 150.000 TWh or even 300.000 TWh.
It is not a far fetched thing to do, if we convert the 850 Quadrillion BTu figure to TWh's we roughly get 240.000 TWh. The energy demand expected by the EIA by the 2040's.
The best renewable technology, without question, is geothermal. I hope that its potency will manifest itself in the coming decades. It has by far the highest yield versus the lowest material requirements of all the renewable technologies.
In order to fulfil the 240.000+ TWh challenge we're going to need everything against it that we we have. BUT every technology needs to be deployed in situations where they truly excel, while keeping a keen eye on material requirements and waste reduction. My future energy mix would look like this : Generation IV nuclear / Nuclear fusion / Geothermal / Hydro / Wind / Solar (in descending order of magnitude)
Lastly I submit to you that I have confidence that extra terrestrial mining practices and future innovations in nuclear fission and fusion are going to render fossil fuels and renewables obsolete alltogether.
I used to be a fervent advocate of renewable energy, not anymore...
This concludes this exhausting session of intellectual mentation and masturbation, I hope you've enjoyed reading it and have been enticed to go look for evidence to form your own opinions.
Free your mind from dogmatism! The answers are to be found in the numbers...